This protocol is designed to focus on exercise as a therapy for preventing the bone mineral loss associated with osteoporosis. Participants in this cross-sectional study will be evaluated according to the type of exercises in which they engage, and several hematologic and musculoskeletal parameters. At this time, this cross-sectional pilot study has nearly all of the participants for which we had planned. Since the group is so small, blood and urine samples collected for biochemical evaluation have been stored until the recruitment phase is completed, so there is very little data yet to allow for preliminary findings. Generally speaking, recruitment has gone well, and we have a sample with which we are happy. We hope that the findings of this pilot study will lead to a larger- scale study of the same design at some point in the future.